package samba4 4.0.0~alpha18.dfsg1-4ubuntu2 failed to install/upgrade: subprocess installed post-installation script returned error exit status 126

[Hemal]

did a apt-get install samba4 and it crashed while upgrading

ProblemType: Package
DistroRelease: Ubuntu 12.04
Package: samba4 4.0.0~alpha18.dfsg1-4ubuntu2
ProcVersionSignature: Ubuntu 3.2.0-35.55-generic-pae 3.2.34
Uname: Linux 3.2.0-35-generic-pae i686
ApportVersion: 2.0.1-0ubuntu15.1
Architecture: i386
Date: Sat Dec 29 19:49:24 2012
ErrorMessage: subprocess installed post-installation script returned error exit status 126
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release i386 (20120423)
MarkForUpload: True
SourcePackage: samba4
Title: package samba4 4.0.0~alpha18.dfsg1-4ubuntu2 failed to install/upgrade: subprocess installed post-installation script returned error exit status 126
UpgradeStatus: No upgrade log present (probably fresh install)